DE69912609T2 - TREATMENT OF AIR-CONTAINED MICRO-ORGANISMS - Google Patents

Description

The present invention relates on the treatment of airborne microorganisms and viruses.

Disinfectants based on essential oils and sterilization compositions are known, e.g. B. from the U.S. Patent No. 5,403,587. This patent relates to antimicrobial Compositions for use in sterilizing, disinfecting and / or cleaning hard surfaces such as kitchen work surfaces, tiles, Porcelain products such as sinks and toilets, floors, windows, Cutlery, glass, dishes and dental and surgical instruments.

• a) eine antimikrobiell wirksame Menge eines etherischen Öls, das in einem Wasserträger gelöst oder dispergiert werden kann und antimikrobielle Eigenschaften zeigt, wenn es in einen Wasserträger eingebracht ist;
• b) eine löslich machende oder dispergierende Menge eines Löslichmachers oder Dispersionsmittels, die genügt, um eine wässrige Lösung oder Dispersion des etherischen Öls in einem Wasserträger zu bilden; und
• c) genügend Wasser, um auf 100 Gew.-% zu ergänzen.

The compositions include:

• a) an antimicrobially effective amount of an essential oil which can be dissolved or dispersed in a water carrier and shows antimicrobial properties when introduced into a water carrier;
• b) a solubilizing or dispersing amount of a solubilizer or dispersing agent sufficient to form an aqueous solution or dispersion of the essential oil in a water carrier; and
• c) enough water to make up to 100% by weight.

Those indicated useful for the invention essential oils, as in U.S. Patent No. 5,403,587, include thyme, lemongrass, Lemons, oranges, anise, clove, roses, lavender, citronell oil; Eucalyptus, Peppermint, camphor, sandalwood and cedar oils.

It is stated that the compositions of the U.S. Patent No. 5,403,587 with conventional blowing agents to distribute as aerosols from usual pressure vessels can be formulated. Blowing agents that can be used include isobutane, n-butane, propane, dimethyl ether and mixtures thereof and chlorofluorocarbons, Fluorocarbons and mixtures thereof.

It is known that treatment microorganisms in the air is difficult. It is in Generally not easy, this entirely from a special place, like that delimited by a space. Besides, is probably any aggressive form of treatment, such as use a spray of a composition which is toxic to microorganisms, a danger to human or animal health within the treated Space.

Bacteria, viruses and fungal spores can be found in the nature as particulate be considered if they are in the air, especially because they often adhere to dust particles or are connected to them. When using an aerosol spray device, a liquid composition, which contains a disinfectant in the form of tiny droplets sprayed to the place to be disinfected. A low collision rate between the liquid droplet and the microorganisms in the air, however, leads to an ineffective killing of microorganisms. In practice this is the consequence Ineffectiveness that the disinfectant composition in one huge Amount would have to be used which creates a health risk. There are more possible Side effects including, when using a perfumed Composition, a resulting strong perfume smell because of the need to use a substantial Amount of disinfectant composition and / or a limited Perfume selection.

RU-A-2068706 discloses a method for disinfecting and cleaning air which includes spraying with a bactericidal preparation, electrically charging the preparation and the air and removing the particles by electrostatic spraying. The sprayed preparation is exposed to ultraviolet radiation at an energy density of 700 to 1500 J / m ³ for 10 to 20 minutes.

An aerosol spray device would have increased effectiveness if the aerosol spray droplets higher Collision rate with the microorganisms. We now have an improved one Developed procedures for disinfecting or sterilizing a site.

According to the present invention there is provided a method of disinfecting or sterilizing a site contaminated by airborne microorganisms and / or viruses, the method comprising applying liquid droplets from a spray device containing a disinfectant or sterilizing composition to the Site, wherein the liquid droplets are given a unipolar charge only by double-layer charging while spraying the liquid droplets from the spray device, the unipolar charge being in a range in which the ratio of charge to mass is at least +/- 1 × 10 ^-4 C / kg.

The disinfection or sterilization composition which is sprayed in the process according to the invention contains at least one antimicrobial agent. Examples of such antimicrobial agents are essential oils such as thyme, lemon grass, lemon, orange, grapefruit, yeast, oregano, anise, clove, cinnamon aldehyde, cinnamon, carvacrol, rose, lavender, citronell oil, eucalyptus, peppermint, camphor, sandalwood, siberian pine, siberian pine sylvestris, tea tree, juniper berry, Litsea cubeba, rosewood, patchouli, vetyver, Cedar wood and mixtures thereof. Other antimicrobial agents that can be used in the present invention include bactericides, e.g. B. quaternary ammonium compounds such as alkyldimethylbenzylammonium saccharinate and benzalkonium chloride, or fungicides such as clotrimazole, miconazole nitrate, organotin compounds, organic acids, halogenated phenols, quaternary ammonium compounds, 8-hydroxyquinoline, diamidines, organic mercury derivatives and the parabens.

It is preferred that the unipolar Charge which is the liquid droplet is awarded exclusively by the interaction between the liquid in the spray device and the spray device itself is generated while the liquid sprayed out of it becomes. It is particularly preferred that the manner in which the liquid droplet a unipolar charge is conferred, even partially connecting the device to any external charge-inducing Device, such as a relatively high voltage source, or any other internal charge-inducing device, such as a battery is. With such an arrangement, the spray device is completely closed, what they are for the use in industrial, institutional as well home Environment.

The spray device is preferably a household pressure spray device without electrical circuits, but which can be held in the hand. Typically points such a device has a capacity in the range of 10 to 2000 ml on and can be done by hand or through an automatic triggering mechanism triggered become. A particularly preferred household device is one hand-held aerosol can.

It is preferred that the droplets are therefore given a ratio of droplet charge to mass of at least +/- 1 × 10 ^-4 C / kg by using an aerosol spray device in which at least one feature of spray head material, size and shape of the spray head opening, The diameter of the riser, properties of the valve and formulation of the disinfectant or sterilizing composition contained in the aerosol spray device is selected to obtain the ratio of droplet charge to mass by charging the bilayer, the droplet being sprayed during the actual spraying of the liquid Droplets from the opening of the aerosol spray device is given a unipolar charge.

As a result of the method according to the invention can Airborne microorganisms and / or viruses compared to known spray processes with great Effectiveness can be eliminated. In particular, much less disinfectant or sterilizing agent than was previously required.

This result is because of the liquid Tröpchen of the aerosol spray obtained unipolar charge. That charge has two effects. The individual droplets become the microorganisms and / or Viruses, including the microorganisms adhering to the dust particles. Because all droplets the same charge polarity wear, they are repelled from each other. Hence there is one little or no coalescence of the droplets, and tend to contrast they tend to expand compared to uncharged droplets spread. If the repulsive forces of the charge in the droplets larger than the surface tension force the droplet are, too the charged droplets caused to separate into a plurality of smaller charged droplets (the Rayleigh limit exceeded) split. This process continues until either the two are up across from standing forces are balanced or the droplet completely evaporated.

Microorganisms in the air, including those stuck to dust particles are usually theirs Environment electrically isolated and are typically based on a potential that is the same as that of their environment. In this state, an isolated microorganism is in a cloud electrically charged liquid droplet so likely a distortion in the arrangement of the electrical Field through the droplets is generated, causing the attraction of the droplets to the Microorganism will be improved. The microorganism will practically the target of a liquid droplet. This improves the interaction between the charged droplets and the microorganisms are combined by the combined effect of the additional Diffusion forces those in the charged droplet cloud caused by the electric field, causing a change the path of every droplet leads, so that it is aimed at a microorganism.

Generally the liquid composition, which into the air using the aerosol spray device sprayed is, preferably a mixture of water and hydrocarbon or an emulsion, or a liquid, by shaking the spray device before use or during the spraying process is converted into an emulsion.

While it is known that all liquid aerosols carry a net negative or positive charge due to the charge of the bilayer or the fragmentation of the liquid droplets, the charge imparted to the droplets of a liquid sprayed from standard devices is only on the order of +/- 1 × 10 ^-8 to 10 ^-5 C / kg.

The invention is based on combining various characteristics of the design of an aerosol spray device, to charge the liquid, while it is sprayed from the aerosol spray device to increase.

• 1. eine Aerosoldose, die die aus der Vorrichtung zu versprühende Zusammensetzung und ein flüssiges oder gasförmiges Treibmittel enthält;
• 2. ein Steigrohr, das in die Dose ragt, wobei das obere Ende des Steigrohrs mit einem Ventil verbunden ist;
• 3. ein über dem Ventil angebrachter Sprühkopf, der gedrückt werden kann, um das Ventil zu betätigen; und
• 4. einen in dem Sprühkopf bereitgestellten Einsatz, der eine Öffnung umfasst, aus welcher die Zusammensetzung gesprüht wird.

A typical aerosol spray device includes:

• 1. an aerosol can containing the composition to be sprayed from the device and a liquid or gaseous propellant;
• 2. a standpipe protruding into the can, the top end of the standpipe connected to a valve;
• 3. a spray head mounted over the valve that can be pressed to actuate the valve; and
• 4. An insert provided in the spray head that includes an opening from which the composition is sprayed.

A preferred aerosol spray device for use in the present invention is in WO 97/12227 described.

It is possible to get through the liquid droplets Choose of the embodiments the aerosol device including the material, the shape and dimensions of the spray head, the spray head insert, of the valve and the riser pipe and the properties of the liquid to be sprayed higher Lend charges so that the required amount of charge is generated will while the liquid in the form of droplets is dispersed.

Some properties of the aerosol system increase the charge of the double layer and the charge exchange between the liquid Formulation and surfaces of the aerosol system. Such an increase is brought about by factors which the turbulence of the flow amplify through the system and the frequency and speed of contact between the liquid and the inner surfaces of the container and the valve and spray head system increase.

As an example, properties of the spray head be optimized to the amount of charge on the liquid sprayed from the container to increase. A small opening in the spray head insert, of size 0.45 mm or less, increased the amount of charge of the liquid sprayed through the spray head. The choice of materials for the spray nozzle can also the amount of charge on the liquid sprayed from the device with material such as nylon, polyester, acetal, PVC and polypropylene, that to increase of the charge amounts tends to enlarge. The Geometry of the opening In use, the amount of charge on the liquid can be optimized to increase while them through the spray head sprayed becomes. Calls, which promote mechanical separation of the liquid result in a better one Charge.

The spray head insert of the spray device can be made of conductive material, semiconducting insulating material or electrostatic charge dissipating material can be molded.

The properties of the riser can be optimized to the amounts in the liquid sprayed from the container to increase. A narrow riser pipe, e.g. B. about 1.27 mm inner diameter, increases the Amounts of charge on the liquid, and the riser material can also be changed to accommodate the load to increase.

Valve properties can be selected which is the relationship from charge to mass of liquid Product while it from the container sprayed will increase. A small tail opening in the housing, from about 0.65 mm, the ratio increases from charge to mass during of spraying. A reduced number of holes in the shaft, e.g. B. 2 × 0.50 mm, increased Moreover the product load during of spraying. The presence of a vapor phase tap helps control the amounts of charge maximize, with a large aperture vapor phase tap, z. B. about 0.50 mm to 1.0 mm, generally gives higher amounts of charge.

Changes in product formulation can also affect the amount of cargo. A wording which is a mixture of hydrocarbon and water or an emulsion contains an immiscible hydrocarbon and water a higher one relationship carry from charge to mass when sprayed out of the aerosol device, as a formulation with either water alone or hydrocarbon alone.

It is preferred that the composition for microorganism treatment for use in the present Invention an oil phase, an aqueous Phase, a surface active Substance, an antibacterial or anti-virus agent and comprises a blowing agent.

The oil phase preferably includes a C ₉ -C ₁₂ hydrocarbon, which is preferably present in the composition in an amount of 2 to 10% by weight.

The surface-active is preferred Substance glyceryl oleate or a polyglycerol oleate, and in the composition preferably present in an amount of 0.1 to 1.0 wt .-%.

The blowing agent is preferably a liquefied Petroleum gas (LPG, "liquified petroleum gas "), which is preferably butane, optionally with the addition of Propane. The blowing agent can be used in an amount of 10 to 90% by weight. dependent on whether the composition is intended to be sprayed as a "wet" or "dry" composition his. For a "wet" composition the blowing agent is preferably in an amount of 20 to 50% by weight, stronger preferably in an amount of 30 to 40% by weight.

The liquid droplets sprayed from the aerosol spray device are generally through have knives in the range from 5 to 100 μm, with a maximum of droplets of about 40 μm. The liquid which is sprayed from the aerosol spray device can contain a predetermined amount of a particulate substance, e.g. B. quartz dust, or a predetermined amount of a volatile solid such as menthol or naphthalene.

The method according to the invention also accelerates as a supplement to kill the microorganisms, the natural ones Process of precipitation of particles contained in the air indirect loading of the particles, making it quick and easy Improve air quality allows becomes.

A can for a typical aerosol spray device is made of aluminum or of painted or unpainted tinplate or the like. The spray head insert can e.g. B. molded from acetal resin. The side opening of the Valve stems can typically take the form of two openings with diameters of 0.51 mm.

The present invention will now by way of example only, with reference to the accompanying drawings described under which:

1 is a schematic cross section through an aerosol spray device according to the invention;

2 a schematic cross section through the valve unit of the device of 1 is;

3 a cross section through the spray head insert in 2 unit shown;

4 the arrangement of the bore of the in 3 spray head shown when viewed in direction A; and

5 the design of the vortex chamber of the 3 shown spray head when viewed in direction B.

What the 1 and 2 relates, an aerosol spray device according to the invention is shown. It includes a can 1 , formed in a conventional manner from aluminum or from painted or unpainted tinplate or the like, with a reservoir 2 for a liquid 3 with such conductivity that the droplets of the liquid can carry a suitable electrostatic charge. There is also a gas under pressure in the can, which is used to drive off the liquid 3 in a can 1 via a piping system that is a riser pipe 4 and a valve and a spray head unit 5 includes, is capable. The riser pipe 4 includes an end 6 which is on a lower outer part of the can 1 ends, and another end 7 which with an end piece 8th the valve unit is connected. The tail 8th is through a mounting unit 9 , which is inserted into an opening in the upper part of the can, secured and closes a lower part 10 one that has a tail opening 11 determines with which the end 7 of the riser 4 connected is. The end piece closes a hole 12 with a relatively small diameter at the lower part 11 and a relatively large diameter at its upper part 13 on. The valve unit also closes a shaft tube 14 one that in the hole 12 of the end piece and is set up so that it is in the hole 12 against the action of the spring 15 is axially displaceable. The valve stem 14 closes an inner hole 16 with one or more side openings (shaft holes) 17 a (see 2 ). The valve unit closes a spray head 18 with a center hole 19 one which the valve stem 14 picks up so the hole 16 of the shaft tube 14 in connection with the bore 19 of the spray head. A passage 20 in the spray head, which is perpendicular to the bore 19 extends, connects the hole 19 with a recess including a support 21 on which a spray head in the form of an insert 22 including a hole 23 that with the culvert 20 communicates, is mounted.

A ring 24 elastomeric material becomes between the outer surface of the valve stem 14 attached and, usually, this sealing ring closes the side opening 17 in the valve stem 14 , The construction of the valve unit is such that the spray head 18 when pushing down the valve stem by hand 14 against the action of the spring 15 drifts down as in 2 shown so that the sealing ring 24 no longer the side opening 17 closes. In this position there is a path from the reservoir 2 for drilling 23 of the spray head created so that the liquid under the pressure of the gas in the can through a pipe system that connects the riser 4 , the tail bore 12 , the valve stem bore 16 who have favourited Spray Head Bore 19 and the culvert 20 includes, can be driven to the spray head.

An opening 27 (not shown in 1 ) is in the wall of the end piece 8th installs and forms a vapor phase tap, reducing the gas pressure in the reservoir 2 can act directly on the liquid flowing through the valve unit. This increases the turbulence of the liquid. It was found that an increased load is delivered when the diameter of the opening 27 is at least 0.76 mm.

The lateral opening is preferably located 17 that the valve stem bore 16 with the tail hole 12 connects, in the form of 2 openings, each with a diameter of not more than 0.51 mm, in order to increase the electrostatic charge generation. In addition, the diameter of the riser pipe 4 preferably as small as possible, e.g. B. 1.2 mm to increase the charge imparted to the liquid. Charge generation is also increased when the diameter of the tip opening 11 as small as possible, e.g. B. is not more than 0.64 mm.

To get on now 3 to obtain, there is a cross section through the spray head insert of the device of the 1 and 2 shown. To simplify the bore 23 as simple cylindrical opening shown in this figure. The hole 23 however, preferably has the z. B. in 4 arrangement shown. The openings of the hole 23 are by the reference number 31 and the parts of the hole defining the opening are identified by the reference number 30 designated. The total circumferential length of the parts defining the opening at the hole exit is denoted by L (in mm), and a is the total area of the opening at the hole exit (in mm ² ), and the values for L and a are as in 4 specified. L / a exceeds 8 and it has been found that this condition is particularly conductive to charge development because it means an increased contact area between the spray head insert and the continuous liquid.

Many different designs can be taken over to be a big one relationship To effect L / a without reducing the cross-sectional area a to a value, which only allow low liquid throughputs would. For example, it is possible Arrangements of the bore of the spray head insert, (i) wherein the bore exit has a plurality of segment-like openings (with or without a central opening); (ii) wherein the exit has a plurality of sector-like openings includes; (iii) taking the openings together form an outlet in the form of a grid or grate; (iv) where the exit is generally cruciform; (v) where the openings together define an outlet in the form of concentric rings; and combinations of these arrangements. Particularly preferred are drilling arrangements of the spray head insert, a tongue-like part protruding into the liquid flow and can be vibrated. This vibration property can be a turbulent flow and a reinforced electrostatic Cause charge separation of the double layer, which allows that more charge in the amount of liquid promoted becomes.

To get on now 5 to obtain, there is a top view of a possible design of a vortex chamber 35 of the spray head insert 22 shown. The vortex chamber closes 4 side channels 36 a, equidistant and tangential to a central area 37 making the hole 23 surrounds. In use, the gas migrates from the reservoir under pressure 2 driven liquid at the passage 20 along and meets the canals 36 perpendicular to the longitudinal axis of the channels. The arrangement of the channels is such that the liquid tends to follow a circular motion before entering the central area 37 and from there into the hole 23 entry. As a result, the liquid is subjected to considerable turbulence, which increases the electrostatic charge in the liquid.

The following comparative examples illustrate the principles of the invention.

COMPARATIVE EXAMPLE 1

An aerosol disinfectant was made from the following components:

The composition was introduced into a tinplate aerosol can with valve units comprising a polyethylene riser 4 of 3 mm, one tail opening 11 of 0.64 mm, a vapor phase tap 27 of 0.64 mm and side openings 17 the valve stem of 4 × 0.61 mm. The spray head 18 was of the Kosmos type, equipped with an Aqua spray head insert 22 of 0.51 / 0.66 mm (both supplied by Precision Valve).

Anyone can use the antibacterial agent suitable substance. For example, an essential oil can be used be, including one or more of the following: lemongrass, lemon, orange, Yeast, clove, thyme, oregano, cinnamon aldehyde, cinnamon and / or carvacrol.

A preferred amount of the antibacterial The composition is 0.2 to 0.25% by weight.

In order to demonstrate the principle of the invention, the amount of charge on the droplets ejected from the can was applied by applying a -10 kV charge from a high voltage source to the seam the can artificially increased to a load to mass ratio of approximately -1 × 10 ^-4 C / kg.

By pushing down the spray head 18 a fine spray of liquid droplets with a charge to mass ratio of -1 × 10 ^-4 C / kg and a throughput of approximately 1.2 g / s was obtained. The droplets were quickly dispersed in the air.

The aerosol spray device described above was with a standard, a known aerosol spray device, filled with the same aerosol formulation. The following protocol was used.

A suspension of Micrococcus luteus at approximately 10 ⁹ cfu / ml in water is prepared. HEPA-filtered air is introduced into an environmental test chamber with a volume of 28 m ³ .

The bacterial suspension becomes 60 seconds into the test chamber with a nebulizer introduced and another 60 seconds with a fan over the Chamber distributed.

A "slit-to-agar" sample collector is activated for 2 hours, samples being obtained after 1, 15, 30, 60 and 120 minutes. The "slit-to-agar" plates are collected. The plates are examined, incubated and the colonies counted to the control results (which are the averages of three experiments are) to be delivered.

The above procedure is done 3 times repeated, but before activating the "slit-to-agar" sample collector, the electrostatically charged is Test product sprayed into the test chamber for 10 seconds. The is again 3 times with the conventional one repeated unloaded trial product.

Those of the loaded and unloaded Results obtained from spray products are compared (after consideration of the control results), and it is shown that with the electrostatic product a significant increase in antibacterial performance is connected in air.

COMPARATIVE EXAMPLE 2

The test organism Micrococcus lutens (ATCC NCTC 2665) obtained from a culture was used as a final suspension with about 10 ⁹ cfu / ml in water. The test chamber had a volume of 28 m ³ , equipped with a connection for HEPA-filtered air and exhaust air. The equipment in the chamber was remotely controlled from a control room. Bacteria were sprayed from a shock nebulizer for 60 seconds and mixed with the room air for a further 60 seconds with a fan. Five glass impingers (AGI) were activated at the subsequent times 1, 14, 29, 59 and 119 minutes after the bacterial release. Each impinger collected air from the test chamber for one minute. After the first impinger finished sampling, a test disinfectant spray was released from an aerosol can into the chamber. The test formulation was:

The spray was released over 10 seconds. The performance of an uncharged aerosol composition was compared to the same aerosol composition with the load artificially applied to the can to demonstrate the principle of the invention. The voltage applied to the can was -3 kV, whereby an aerosol with a charge to mass ratio of -1.3 × 10 ^-4 C / kg was obtained. The following AGIs documented the effect of applying charge to the aerosol on the concentration of microorganisms contained in the air. The number of bacteria collected in the AGI was determined by taking 0.1 ml of liquid from the AGI and placing it on an agar plate, this was repeated once. The plates were then incubated at 30 ° C for 72 hours. Colonies were counted and the mean of the 2 plates was shown in the results below:

Results Table 1: Number of Micrococcus lutens collected in the impinger

Claims (15)

A method of disinfecting or sterilizing a site contaminated by airborne microorganisms and / or viruses, the method comprising applying liquid droplets from a spray device comprising a disinfecting or sterilizing composition to the site, characterized in that the liquid Droplets are given a unipolar charge only by double-layer charging during the spraying of the liquid droplets from the spray device, the unipolar charge being in a range in which the charge to mass ratio is at least +/- 1 × 10 ^-4 C / kg. Method according to claim 1, wherein the spray device is an aerosol spray device. Method according to claim 1 or claim 2, wherein the disinfecting or sterilizing composition is an emulsion. Procedure according to a the preceding claims, being the liquid droplet have a diameter in the range from 5 to 100 μm. Procedure according to a the preceding claims, being the liquid droplet a unipolar charge is conferred without its charge being an internal or external charge inducing device becomes. A method according to claim 5, wherein the droplets are given a droplet charge to mass ratio of at least +/- 1 x 10 ^-4 C / kg using an aerosol spray in which at least one feature of spray head material, size and shape of the spray head opening, The diameter of the riser, properties of the valve and formulation of the disinfectant or sterilizing composition in the aerosol spray device is selected to maintain the droplet charge to mass ratio by double layer charging, the pottles being unipolar during the actual spraying of the liquid droplets from the opening of the aerosol spray device Charge is awarded. Procedure according to a the preceding claims, the disinfecting or sterilizing composition being an oil phase, an aqueous Phase, a surface active Substance, an antibacterial agent, a fungicide or an anti-viral agent and one Includes blowing agents. Method according to claim 7, wherein the antibacterial or anti-virus agent comprises an essential oil, which one selected is made from thyme, lemongrass, lemon, orange, grapefruit, yeast, Oregano, anise, clove, cinnamon aldehyde, cinnamon, carvacrol, rose, lavender, citronella, Eucalyptus, peppermint, camphor, sandalwood, juniper berry, Siberian Pine needle, Pinus sylvestris, tea tree, Litsea cubeba, rosewood, Patchouli, vetyver, cedar and mixtures thereof. Method according to claim 7, wherein the antibacterial agent is a quaternary ammonium compound. A method according to any one of claims 7 to 9, wherein the oil phase includes a C ₉ -C ₁₂ hydrocarbon. A method according to claim 10, wherein the C ₉ -C ₁₂ hydrocarbon is present in the composition in an amount of 2 to 10% by weight. Procedure according to a of claims 7 to 11, the surface-active Substance is a glyceryl oleate or a polyglycerol oleate. Procedure according to a of claims 7 to 12, the surface-active Substance in an amount of 0.1 to 1.0% by weight in the composition is available. Procedure according to a of claims 7 to 13, the blowing agent being a liquefied petroleum gas. Method according to claim 14, wherein the blowing agent in an amount of 20 to 50 wt .-% in the composition is present.